OBJECTIVES: Cytogenetic and reproductive studies of murine Robertsonian translocation carriers. Analysis of adult and fetal somatic and gonadal tissues using chromosomal banding techniques in order to study meiotic nondisjunction and characteristics of aneuploid progeny from translocation heterozygotes. Cytogenetic and dermatoglyphic analysis of patients with congenital defects, recognized dysmorphic syndromes, abnormal gonadal development and function, and other genetic disorders. Techniques used for cytogenetic studies include Giemsa-, quinacrine-, and centromeric-banding, as well as fluorescent-Giemsa analysis of chromosomal replication sequences. Cytogenetic, dermatoglyphic, and other clinical studies are correlated. Karyotypic evaluation of potentially abnormal tissues. These studies utilize a variety of chromosomal banding methods for analysis of tissues from laboratory animals (primate and murine) suspected of having chromosomal abnormalities. Relationship of cytogenetic findings to genetic background, development of tumors, and reproductive fitness is emphasized.